What specific fixation do you mean? I've only seen fans giving their opinions on the idea, not much different to your post
I really don't understand the fixation that some people have about immediately shooting down the idea of the band recruiting a female singer. I personally think it's a bad idea. Although there are several factors to consider on what's best for the band thinking you know better than the band seems like a bad idea. The band can do whatever they want (it's not like they care about your suggestion or anything) but it feels strange that you are the expert on what LP should do after Chester's passing. We already saw by your username that you're a diehard LP fan but your takes are underwhelming.
I’m waiting on word from the band whether this is actually legit or not, but if it does turn out to truly be factual then I’m open to whatever the band has planned and open to whatever they decide on.
It's not a fixation, it's more fans reacting to rumours/speculation that's been put out by different sources that have suggested that the band want a female vocalist. Personally I'll be happy with whatever the band do, as long as they do something. Would love a new tour/album.